A comprehensive preanalytical protocol for fresh solid tumor biospecimens.

Nearly seventy percent of diagnostic lab test errors occur due to variability in preanalytical factors. These are the parameters involved with all aspects of tissue processing, starting from the time tissue is collected from the patient in the operating room, until it is received and tested in the laboratory. While there are several protocols for transporting fixed tissue, organs, and liquid biopsies, such protocols are lacking for transport and handling of live solid tumor tissue specimens. There is a critical need to establish preanalytical protocols to reduce variability in biospecimen integrity and improve diagnostics for personalized medicine. Here, we provide a comprehensive protocol for the standard collection, handling, packaging, cold-chain logistics, and receipt of solid tumor tissue biospecimens to preserve tissue viability.

Comparing Accuracy of Helicobacter pylori Identification Using Traditional Hematoxylin and Eosin-Stained Glass Slides With Digital Whole Slide Imaging.

With advancements in the field of digital pathology, there has been a growing need to compare the diagnostic abilities of pathologists using digitized whole slide images against those when using traditional hematoxylin and eosin (H&E)-stained glass slides for primary diagnosis. One of the most common specimens received in pathology practices is an endoscopic gastric biopsy with a request to rule out Helicobacter pylori (H. pylori) infection. The current standard of care is the identification of the organisms on H&E-stained slides. Immunohistochemical or histochemical stains are used selectively. However, due to their small size (2-4 µm in length by 0.5-1 µm in width), visualization of the organisms can present a diagnostic challenge. The goal of the study was to compare the ability of pathologists to identify H. pylori on H&E slides using a digital platform against the gold standard of H&E glass slides using routine light microscopy. Diagnostic accuracy rates using glass slides vs digital slides were 81% vs 72% (P = .0142) based on H&E slides alone. When H. pylori immunohistochemical slides were provided, the diagnostic accuracy was significantly improved to comparable rates (96% glass vs 99% digital, P = 0.2199). Furthermore, differences in practice settings (academic/subspecialized vs community/general) and the duration of sign-out experience did not significantly impact the accuracy of detecting H. pylori on digital slides. We concluded that digital whole slide images, although amenable in different practice settings and teaching environments, does present some shortcomings in accuracy and precision, especially in certain circumstances and thus is not yet fully capable of completely replacing glass slide review for identification of H. pylori. We specifically recommend reviewing glass slides and/or performing ancillary stains, especially when there is a discrepancy between the degree of inflammation and the presence of microorganisms on digital images.

Characterization of mismatch-repair/microsatellite instability-discordant endometrial cancers.

BACKGROUND: Mismatch-repair (MMR)/microsatellite instability (MSI) status has therapeutic implications in endometrial cancer (EC). The authors evaluated the concordance of testing and factors contributing to MMR expression heterogeneity. METHODS: Six hundred sixty-six ECs were characterized using immunohistochemistry (IHC), MSI testing, and mut-L homolog 1 (MLH1) methylation. Select samples underwent whole-transcriptome analysis and next-generation sequencing. MMR expression of metastatic/recurrent sites was evaluated. RESULTS: MSI testing identified 27.3% of cases as MSI-high (n = 182), MMR IHC identified 25.1% cases as MMR-deficient (n = 167), and 3.8% of cases (n = 25) demonstrated discordant results. A review of IHC staining explained discordant results in 18 cases, revealing subclonal loss of MLH1/Pms 1 homolog 2 (PMS2) (n = 10) and heterogeneous MMR IHC (mut-S homolog 6 [MSH6], n = 7; MLH1/PMS2, n = 1). MSH6-associated Lynch syndrome was diagnosed in three of six cases with heterogeneous expression. Subclonal or heterogeneous cases had a 38.9% recurrence rate (compared with 16.7% in complete MMR-deficient cases and 9% in MMR-proficient cases) and had abnormal MMR IHC results in all metastatic recurrent sites (n = 7). Tumors with subclonal MLH1/PMS2 demonstrated 74 differentially expressed genes (determined using digital spatial transcriptomics) when stratified by MLH1 expression, including many associated with epithelial-mesenchymal transition. CONCLUSIONS: Subclonal/heterogeneous MMR IHC cases showed epigenetic loss in 66.7%, germline mutations in 16.7%, and somatic mutations in 16.7%. MMR IHC reported as intact/deficient missed 21% of cases of Lynch syndrome. EC with subclonal/heterogeneous MMR expression demonstrated a high recurrence rate, and metastatic/recurrent sites were MMR-deficient. Transcriptional analysis indicated an increased risk for migration/metastasis, suggesting that clonal MMR deficiency may be a driver for tumor aggressiveness. Reporting MMR IHC only as intact/deficient, without reporting subclonal and heterogeneous staining, misses opportunities for biomarker-directed therapy. PLAIN LANGUAGE SUMMARY: Endometrial cancer is the most common gynecologic cancer, and 20%-40% of tumors have a defect in DNA proofreading known as mismatch-repair (MMR) deficiency. These results can be used to guide therapy. Tests for this defect can yield differing results, revealing heterogeneous (mixed) proofreading capabilities. Tumors with discordant testing results and mixed MMR findings can have germline or somatic defects in MMR genes. Cells with deficient DNA proofreading in tumors with mixed MMR findings have DNA expression profiles linked to more aggressive characteristics and cancer spread. These MMR-deficient cells may drive tumor behavior and the risk of spreading cancer.

Histologic manifestations of ocrelizumab-associated intestinal and hepatic injury in patients with multiple sclerosis.

AIMS: Ocrelizumab is a humanized anti-CD20-monoclonal antibody that has recently been approved for the treatment of certain types of multiple sclerosis. Isolated case reports of ocrelizumab-associated colitis have been reported in the literature. We present a case series of ocrelizumab-associated intestinal injury with a focus on histopathologic features and report a case of ocrelizumab-associated hepatitis. METHODS AND RESULTS: A retrospective computerized search was conducted from 03/2017 to 08/2022, which identified six patients with suspected or clinically confirmed ocrelizumab-associated intestinal injury and one patient with hepatic injury. Pertinent clinical, endoscopic, and histopathologic findings were reviewed and recorded. Seven patients (six female, one male) were identified with ages ranging from 24 to 68 years. The presenting symptoms included diarrhoea (n = 5), abdominal pain (n = 3), hematochezia (n = 2), and vomiting (n = 1), nausea (n = 1) fever (n = 1), and weight loss (n = 1). Endoscopic findings ranged from normal (n = 1) to patchy colonic inflammation with or without ulceration (n = 4) and decreased mucosal vascular pattern in the rectum (n = 1). Crohn's disease was clinically suspected in two patients and ulcerative colitis in one patient. None of the patients had a prior confirmed diagnosis of inflammatory bowel disease. Histologic patterns of initial colonic injury included acute colitis/proctitis (n = 5), and chronic active colitis (n = 1). Follow-up ranged from 1 to 3 years and 10 months. All patients were alive at follow-up. Follow-up biopsies were available for four patients and findings included focal acute colitis (n = 1), apoptotic colopathy (n = 1) lymphocytic colitis (n = 1), and normal mucosa (n = 1). Four patients were treated with steroids and ocrelizumab was discontinued in three patients. Two patients were symptomatically managed with subsequent resolution of symptoms. The liver biopsy from the patient with a marked hepatic pattern of liver enzyme elevation showed an acute hepatitis pattern of injury with prominent centrilobular necrosis, which resolved upon discontinuation of the drug and treatment with steroids and azathioprine. CONCLUSIONS: The histologic manifestations of ocrelizumab-associated intestinal injury are variable and can mimic inflammatory bowel disease. Hepatic injury can rarely manifest as an acute hepatitis pattern of injury with necrosis. Identifying ocrelizumab-associated injury is paramount in determining management, which often includes discontinuation of ocrelizumab therapy, and/or administration of immunosuppressive therapy.

Predictive Value of MUC5AC Signature in Pancreatic Ductal Adenocarcinoma: A Hypothesis Based on Preclinical Evidence.

Mucin 5AC (MUC5AC) glycoprotein plays a crucial role in carcinogenesis and drug sensitivity in pancreatic ductal adenocarcinoma (PDAC), both individually and in combination with other mucins. Its function and localization are glycoform-specific. The immature isoform (detected by the CLH2 monoclonal antibody, or mab) is usually in the perinuclear (cytoplasmic) region, while the mature (45 M1, 2-11, Nd2) variants are in apical and extracellular regions. There is preclinical evidence suggesting that mature MUC5AC has prognostic and predictive (response to treatment) value. However, these findings were not validated in clinical studies. We propose a MUC5AC signature with three components of MUC5AC-localization, variant composition, and intensity-suggesting a reliable marker in combination of variants than with individual MUC5AC variants alone. We also postulate a theory to explain the occurrence of different MUC5AC variants in abnormal pancreatic lesions (benign, precancerous, and cancerous). We also analyzed the effect of mature MUC5AC on sensitivity to drugs often used in PDAC management, such as gemcitabine, 5-fluorouracil, oxaliplatin, irinotecan, cisplatin, and paclitaxel. We found preliminary evidence of its predictive value, but there is a need for large-scale studies to validate them.

Histologic Analysis of Endoscopic Ultrasound-Guided Through the Needle Microforceps Biopsies Accurately Identifies Mucinous Pancreas Cysts.

BACKGROUND & AIMS: It is a challenge to accurately assess pancreatic cystic lesions (PCLs) and determine their risk. We compared the yield of tissue acquired with endoscopic ultrasound (EUS)-guided microforceps (through the needle tissue biopsy [TTNB]) with that of samples collected by EUS-guided fine-needle-aspiration (EUS-FNA), and the accuracy of analyses of each sample type in the diagnosis of mucinous PCLs. METHODS: We performed a prospective open-label study of 114 consecutive adults (56.1% women; mean age, 64.2 y) undergoing EUS-FNA evaluation of PCLs (mean size, 35 mm) at 7 centers, from June 20, 2016, through August 31, 2018. Samples were collected from each cyst by FNA and microforceps; samples collected by FNA were analyzed by cytology and samples collected by TTNB were analyzed by histology. Acquisition yield was defined as the percentage of specimens collected that were adequate for cytologic or histologic analysis. Diagnoses of mucinous cysts were made based on identification of pancreatic mucinous epithelium by cytology analysis of FNA samples or histologic analysis of TTNB samples. Surgical specimens were used as the reference standard when available. RESULTS: The EUS-guided microforceps were successfully inserted into 97.4% (111 of 114) of PCLs. Tissue acquisition yield was significantly higher with TTNB (95 of 114; 83.3%) than FNA (43 of 114; 37.7%) (P < .001). Sixty-one PCLs were determined to be mucinous based on TTNB analysis (53.5%) vs 11 with FNA analysis (9.6%) (P < .001). Among PCLs categorized as equivocal, based on the level of carcinoembryonic antigen, TTNB analysis found 50% (41 of 82) to be mucinous and FNA analysis found 8.5% (7 of 82) to be mucinous (P < .001). Findings from analyses of samples collected by TTNB were 100% concordant with findings from histologic analysis of surgical specimens (14 of 14), whereas only 3 of 14 findings from analysis of samples collected by FNA were in agreement with findings from surgical specimens (21.4%) (P < .001). Four of 5 mucinous PCLs with advanced neoplasia (80%) were detected with TTNB compared with none with FNA (P = .04). Self-limited intracystic bleeding occurred in 7 patients (6.1%), and acute pancreatitis in 6 patients (5.3%). CONCLUSIONS: In a multicenter prospective study of patients undergoing EUS-FNA for evaluation of PCLs, we found TTNB collection of tissues for histologic analysis to be safe and feasible, with an acquisition yield of 83.3%. Histologic analysis of samples collected by TTNB identified a larger proportion of mucinous PCLs compared with cytologic analysis of samples collected by FNA-even among samples categorized as equivocal, based on the level of carcinoembryonic antigen. More samples collected by TTNB than FNA were found to have advanced neoplasia. Clinicaltrials.gov no: NCT02979509.

Associations of mammographic breast density with breast stem cell marker-defined breast cancer subtypes.

PURPOSE: High mammographic breast density is a strong, well-established breast cancer risk factor. Whether stem cells may explain high breast cancer risk in dense breasts is unknown. We investigated the association between breast density and breast cancer risk by the status of stem cell markers CD44, CD24, and ALDH1A1 in the tumor. METHODS: We included 223 women with primary invasive or in situ breast cancer and 399 age-matched controls from Mayo Clinic Mammography Study. Percent breast density (PD), absolute dense area (DA), and non-dense area (NDA) were assessed using computer-assisted thresholding technique. Immunohistochemical analysis of the markers was performed on tumor tissue microarrays according to a standard protocol. We used polytomous logistic regression to quantify the associations of breast density measures with breast cancer risk across marker-defined tumor subtypes. RESULTS: Of the 223 cancers in the study, 182 were positive for CD44, 83 for CD24 and 52 for ALDH1A1. Associations of PD were not significantly different across t marker-defined subtypes (51% + vs. 11-25%: OR 2.83, 95% CI 1.49-5.37 for CD44+ vs. OR 1.87, 95% CI 0.47-7.51 for CD44-, p-heterogeneity = 0.66; OR 2.80, 95% CI 1.27-6.18 for CD24+ vs. OR 2.44, 95% CI 1.14-5.22 for CD24-, p-heterogeneity = 0.61; OR 3.04, 95% CI 1.14-8.10 for ALDH1A1+ vs. OR 2.57. 95% CI 1.30-5.08 for ALDH1A1-, p-heterogeneity = 0.94). Positive associations of DA and inverse associations of NDA with breast cancer risk were similar across marker-defined subtypes. CONCLUSIONS: We found no evidence of differential associations of breast density with breast cancer risk by the status of stem cell markers. Further studies in larger study populations are warranted to confirm these associations.

Differential expression of Annexin 2, SPINK1, and Hsp60 predict progression of prostate cancer through bifurcated WHO Gleason score categories in African American men.

BACKGROUND: Although studies have observed several markers correlate with progression of prostate cancer (PCa), no specific markers have been identified that accurately predict the progression of this disease, even in African American (AA) men who are generally at higher risk than other ethnic groups. The primary goal of this study was to explore whether three markers could predict the progression of PCa. METHOD: We investigated protein expression of Annexin 2 (ANX2), serine peptidase inhibitor, kazal type 1(SPINK1)/tumor-associated trypsin inhibitor (TATI), and heat shock protein 60 (Hsp60) in 79 archival human prostate trans-rectal ultrasound (TRUS) biopsy tissues according to a modified World Health Organization (WHO) classification: normal (WHO1a), Gleason Score (GS6 (WHO1b), GS7 subgroups (WHO2 = 3 + 4, WHO3 = 4 + 3), GS8 (WHO4), and GS9-10 (WHO5). AA men aged 41-90 diagnosed from 1990 to 2013 at Howard University were included. Automated staining assessed expression of each biomarker. Spearman correlation assessed the direction and relationship between biomarkers, WHO and modified WHO GS, age, and 5-year survival. A two-tailed t-test and ANOVA evaluated biomarkers expression in relationship to WHO normal and other GS levels, and between WHO GS levels. A logistic and linear regression analysis examined the relationship between biomarker score and WHO GS categories. Kaplan-Meier curves graphed survival. RESULTS: ANX2 expression decreased monotonically with the progression of PCa while expression of SPINK1/TATI and Hsp60 increased but had a more WHO GS-specific effect; SPINK1/TATI differed between normal and GS 2-6 and HSP60 differed between GS 7 and GS 2-6. WHO GS was found to be significantly and negatively associated with ANX2, and positively with SPINK1/TATI and Hsp60 expression. High SPINK1/TATI expression together with the low ANX2 expression at higher GS exhibited a bi-directional relationship that is associated with PCa progression and survival. CONCLUSION: Importantly, the data reveal that ANX2, and SPINK1/TAT1 highly associate with WHO GS and with the transition from one stage of PrCa to the next in AA men. Future research is needed in biracial and larger population studies to confirm this dynamic relationship between ANX2 and SPINK1 as independent predictors of PCa progression in all men.

MYC amplification in subtypes of breast cancers in African American women.

BACKGROUND: MYC overexpression is associated with poor prognosis in breast tumors (BCa). The objective of this study was to determine the prevalence of MYC amplification and associated markers in BCa tumors from African American (AA) women and determine the associations between MYC amplification and clinico-pathological characteristics. METHODS: We analyzed 70 cases of well characterized archival breast ductal carcinoma specimens from AA women for MYC oncogene amplification. Utilizing immune histochemical analysis estrogen receptor (ER), progesterone receptor (PR), and (HER2/neu), were assessed. Cases were Luminal A (ER or PR+, Ki-67 < 14%), Luminal B (ER or PR+, Ki-67 = > 14% or ER or PR+ HER2+), HER2 (ER-, PR-, HER2+), and Triple Negative (ER-, PR-, HER2-) with basal-like phenotype. The relationship between MYC amplification and prognostic clinico-pathological characteristics was determined using chi square and logistic regression modeling. RESULTS: Sixty-five (97%) of the tumors showed MYC gene amplification (MYC: CEP8 > 1). Statistically significant associations were found between MYC amplification and HER2-amplified BCa, and Luminal B subtypes of BCa (p < 0.0001), stage (p < 0.001), metastasis (p < 0.001), and positive lymph node status (p = 0.039). MYC amplification was associated with HER2 status (p = 0.01) and tumor size (p = 0.01). High MYC amplification was seen in grade III carcinomas (MYC: CEP8 = 2.42), pre-menopausal women (MYC: CEP8 = 2.49), PR-negative status (MYC: CEP8 = 2.42), and ER-positive status (MYC: CEP8 = 2.4). CONCLUSIONS: HER2 positive BCas in AA women are likely to exhibit MYC amplification. High amplification ratios suggest that MYC drives HER2 amplification, especially in HER2 positive, Luminal B, and subtypes of BCa.

Tissue-based multigene expression tests for pretreatment prostate cancer risk assessment: current status and future perspectives.

Prostate cancer is a highly prevalent disease with ample spectrum of aggressiveness and treatment options. Low-risk disease can be safely managed by nonintervention strategies, such as active surveillance; however, accurate risk assessment is warranted. Molecular tests have been developed and validated to complement standard clinicopathological parameters and help to improve risk stratification in prostate cancer. Herein, we review selected tissue-based assays, including genomic prostate score, cell cycle progression score and genomic classifier, with particular emphasis on their role in patient risk assessment in a pretreatment setting, in view of their current or potential utilization in active surveillance.

Molecular Pathology of Pancreatic Cystic Lesions with a Focus on Malignant Progression.

The malignant progression of pancreatic cystic lesions (PCLs) remains understudied with a knowledge gap, yet its exploration is pivotal for effectively stratifying patient risk and detecting cancer at its earliest stages. Within this review, we delve into the latest discoveries on the molecular level, revealing insights into the IPMN molecular landscape and revised progression model, associated histologic subtypes, and the role of inflammation in the pathogenesis and malignant progression of IPMN. Low-grade PCLs, particularly IPMNs, can develop into high-grade lesions or invasive carcinoma, underscoring the need for long-term surveillance of these lesions if they are not resected. Although KRAS and GNAS remain the primary oncogenic drivers of neoplastic development in IPMNs, additional genes that are important in tumorigenesis have been recently identified by whole exome sequencing. A more complete understanding of the genes involved in the molecular progression of IPMN is critical for effective monitoring to minimize the risk of malignant progression. Complicating these strategies, IPMNs are also frequently multifocal and multiclonal, as demonstrated by comparative molecular analysis. Algorithms for preoperative cyst sampling and improved radiomic techniques are emerging to model this spatial and temporal genetic heterogeneity better. Here, we review the molecular pathology of PCLs, focusing on changes associated with malignant progression. Developing models of molecular risk stratification in PCLs which can complement radiologic and clinical features, facilitate the early detection of pancreatic cancer, and enable the development of more personalized surveillance and management strategies are summarized.

Automated imaging analysis of Ki-67 immunohistochemistry on whole slide images of cell blocks from pancreatic neuroendocrine neoplasms.

INTRODUCTION: Accurate grading of pancreatic neuroendocrine tumors (PanNETs) relies on the assessment of Ki-67 immunohistochemistry (IHC). While digital imaging analysis (DIA) has been employed for Ki-67 IHC assessment in surgical specimens, its applicability to cytologic specimens remains underexplored. This study aimed to evaluate an automated DIA for assessing Ki-67 IHC on PanNET cell blocks. MATERIALS AND METHODS: The study included 61 consecutive PanNETs and 5 pancreatic neuroendocrine carcinomas. Ki-67 IHC slides from cell blocks were digitally scanned into whole slide images using Philips IntelliSite Scanners and analyzed in batches using the Visiopharm Ki-67 App in a digital workflow. Ki-67 scores obtained through DIA were compared to pathologists' manual scores. RESULTS: The Pearson correlation coefficient of the percentage of Ki-67-stained nuclei between DIA reads and the originally reported reads was 0.9681. Concordance between DIA Ki-67 grades and pathologists' Ki-67 grades was observed in 92.4% (61/66) of cases with the calculated Cohen's Kappa coefficient of 0.862 (almost perfect agreement). Discordance between DIA and pathologists' consensus reads occurred in 5 PanNET cases which were upgraded from G1 to G2 by DIA due to contaminated Ki-67-stained inflammatory cells. CONCLUSIONS: DIA demonstrated excellent concordance with pathologists' assessments, with only minor grading discrepancies. However, the essential role of pathologists in confirming results is emphasized to enhance overall accuracy.

Perivascular Epithelioid Cell-Family Tumors in Children, Adolescents and Young Adults:Clinicopathologic Features in 70 Cases.

CONTEXT.­: Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors of uncertain histogenesis expressing smooth muscle and melanocytic markers. The clinicopathologic spectrum in young patients is not well documented. OBJECTIVE.­: To describe a multi-institutional series of PEComas in children, adolescents, and young adults. DESIGN.­: PEComas, not otherwise specified (NOS); angiomyolipomas (AMLs); lymphangioleiomyomatosis; and clear cell sugar tumors were retrospectively identified from 6 institutions and authors' files. RESULTS.­: Seventy PEComas in 64 patients (median age, 15 years) were identified. They were more common in females (45 of 64 patients), occurring predominately in kidney (53 of 70), followed by liver (6 of 70). Thirty-four patients had confirmed tuberous sclerosis complex (TSC), 3 suspected TSC mosaicism, 2 Li-Fraumeni syndrome (LFS) and 1 neurofibromatosis type 1. Most common variants were classic (49 of 70) and epithelioid (8 of 70) AML. Among patients with AMLs, most (34 of 47) had TSC, and more TSC patients had multiple AMLs (15 of 36) than non-TSC patients (2 of 13). Two TSC patients developed malignant transformation of classic AMLs: 1 angiosarcomatous and 1 malignant epithelioid. Lymphangioleiomyomatosis (5 of 70) occurred in females only, usually in the TSC context (4 of 5). PEComas-NOS (6 of 70) occurred exclusively in non-TSC patients, 2 of whom had LFS (2 of 6). Three were malignant, 1 had uncertain malignant potential, and 2 were benign. All 4 PEComas-NOS in non-LFS patients had TFE3 rearrangements. CONCLUSIONS.­: Compared to the general population, TSC was more prevalent in our cohort; PEComas-NOS showed more frequent TFE3 rearrangements and possible association with LFS. This series expands the spectrum of PEComas in young patients and demonstrates molecular features and germline contexts that set them apart from older patients.

Metastatic High-Grade Endometrial Stromal Sarcoma with BCOR Translocation to the Pleural Fluid: A Case Report.

Sarcomas in cytology fluids are uncommon, accounting for an estimated 3-6% of malignant effusions. High-grade endometrial stromal sarcomas are uncommon malignancies, whose true frequency is not well defined. We present a case of high-grade endometrial stromal sarcoma with a BCOR translocation metastatic to the pleural fluid. A 31-year-old female with a long-standing history of abnormal uterine bleeding underwent needle core biopsy, which showed a high-grade endometrial stromal sarcoma with a BCOR translocation. In the months following her diagnosis, the patient underwent multiple cycles of chemotherapy along with radiation therapy, but had disease progression. She then presented with bilateral pleural effusions. Cytology from the pleural effusions showed single cells and three-dimensional clusters of spindle-shaped to epithelioid cells. The cell block showed many groups of the atypical cells. The histologic and immunophenotypic features were consistent with metastatic endometrial stromal sarcoma. Ten months after initial diagnosis and two months after positive pleural fluid cytology the patient was deceased. Malignant pleural fluids with sarcoma metastases are not common. Endometrial stromal sarcomas are infrequent malignancies and those with BCOR translocations are recently described with a small number of cases reported. Pleural fluid metastasis of high-grade endometrial stromal sarcoma with BCOR translocation has not, to our knowledge, been described in the literature.

Understanding the Clinical Significance of MUC5AC in Biliary Tract Cancers.

Biliary tract cancers (BTC) arise from biliary epithelium and include cholangiocarcinomas or CCA (including intrahepatic (ICC) and extrahepatic (ECC)) and gallbladder cancers (GBC). They often have poor outcomes owing to limited treatment options, advanced presentations, frequent recurrence, and poor response to available systemic therapy. Mucin 5AC (MUC5AC) is rarely expressed in normal biliary epithelium, but can be upregulated in tissues of benign biliary disease, premalignant conditions (e.g., biliary intraepithelial neoplasia), and BTCs. This mucin's numerous glycoforms can be divided into less-glycosylated immature and heavily-glycosylated mature forms. Reported MUC5AC tissue expression in BTC varies widely, with some associations based on cancer location (e.g., perihilar vs. peripheral ICC). Study methods were variable regarding cancer subtypes, expression positivity thresholds, and MUC5AC glycoforms. MUC5AC can be detected in serum of BTC patients at high concentrations. The hesitancy in developing MUC5AC into a clinically useful biomarker in BTC management is due to variable evidence on the diagnostic and prognostic value. Concrete conclusions on tissue MUC5AC are difficult, but serum detection might be relevant for diagnosis and is associated with poor prognosis. Future studies are needed to further the understanding of the potential clinical value of MUC5AC in BTC, especially regarding predictive and therapeutic value.

Differential Expression and Diagnostic Value of MUC5AC Glycoforms in Pancreatic Ductal Adenocarcinoma.

We explored the differential expression and diagnostic value of two significant Mucin 5AC (MUC5AC) glycoforms, less-glycosylated immature (IM) and heavily-glycosylated mature (MM), in neoplastic diseases (NpD), including pancreatic ductal adenocarcinoma (PDA) and neuroendocrine tumors (NET), and non-neoplastic (non-NpD) diseases. Commercially available tissue microarray (TMA) was constructed from 96 patients, including 38 primary PDA (PT), 5 metastatic lesions (ML), 11 NET, and the rest being non-NpD tissues. Immunohistochemistry for MUC5AC was performed using CHL2 and 45M1 clones for IM and MM isoforms, respectively. MUC5AC (both glycoforms) are not detected in non-NpD. In MUC5AC-positive neoplastic tissues, IM was localized to the cytoplasm (Cy) while MM was identified in apical (Ap) and extracellular (Ec) regions too. One ML positive (omentum) in the TMA expressed both. For PDA vs. non-PDA, the sensitivity (SN) was higher with MM ± IM (71%) than MM (47%) or IM (65%)-alone. The specificity (SP) was 100% with MM-alone, which dropped with the addition of IM (96%) or IM-alone (93%). For NpD vs. non-NpD, the SN (MM + IM-59%, IM-55%, MM-37%) was inferior, and SP was 100% for both glycoforms (MM ± IM). The combination of MUC5AC glycoforms has high SP and reasonable SN to diagnose PDA. They have the potential to be a reliable diagnostic marker and should be investigated further in more extensive studies.

A Comparison of Single Dimension and Volume Measurements in the Risk Stratification of Pancreatic Cystic Lesions.

The incidence of pancreatic cystic lesions (PCLs) has been rising due to improvements in imaging. Of these, intraductal papillary mucinous neoplasms (IPMNs) are the most common and are thought to contribute to almost 20% of pancreatic adenocarcinomas. All major society guidelines for the management of IPMNs use size defined by maximum diameter as the primary determinant of whether surveillance or surgical resection is recommended. However, there is no consensus on how these measurements should be obtained or whether a single imaging modality is superior. Furthermore, the largest diameter may fail to capture the complexity of PCLs, as most are not perfectly spherical. This article reviews current PCL measurement techniques in CT, MRI, and EUS and posits volume as a possible alternative to the largest diameter.